The present technology relates to a device and a method for streaming distribution, a device and a method for streaming reception, a streaming system, a program, and a recording medium, and particularly to a device and a method for streaming distribution, a device and a method for streaming reception, a streaming system, a program, and a recording medium that can reduce a processing load relating to the display of subtitles in streaming.
Standardization in Internet streaming such as IPTV (Interned Protocol Television) and the like for distributing moving images using an IP (Internet Protocol) has recently been under way. For example, standardization of systems applied to VoD (Video on Demand) streaming based on HTTP (HyperText Transfer Protocol) streaming and live streaming has been under way. In work for such standardization, consideration is given to the use of an MP4 file format as a format used in a container layer.
In addition, when there are subtitles as a constituent element of HTTP streaming, TTML (Timed Text Markup Language) defined by the W3C (The World Wide Web Consortium) is often used. TTML is also being adopted by other standardization groups, and is drawing attention as a dominant format.
TTML is principally divided into two types according to the classifications of document instances. One is a document instance referred to as an “Initialization Document instance,” which is an instance formed by a description specifying the color, the font, the display position and the like of characters displayed as subtitles, for example. The other is a document instance referred to as a “Body Document instance,” which is an instance formed by a description such as a character string actually displayed as subtitles.
When TTML is used, character strings described in “Body Document instances” can be displayed in succession according to the color, the font, the display position and the like of characters, the color, the font, the display position and the like being described in an “Initialization Document instance,” for example.
Specifically, a receiver for receiving a stream and making display can be configured to analyze an “Initialization Document instance” first, thereby identify the color, the font, the display position and the like of characters, and thereafter display a character string obtained by analyzing a “Body Document instance.” That is, the receiver does not need to analyze a rendering context as defining information such as the color, the font, the display position and the like of characters each time, so that a processing load relating to the display of subtitles can be reduced.
In addition, a stream receiving device capable of realizing efficient band management and efficient channel switching processing on the side of a receiver in an organization format in which a 2D program and a 3D program are mixed with each other has been proposed (see Japanese Patent Laid-Open No. 2011-097227, for example).